Protective Helmet with Expandable Bladders for Rotational Force Dissipation
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Solution Overview
Problem
Existing helmets fail to effectively mitigate both linear and rotational forces applied to the head, leading to inadequate protection against traumatic brain injuries, as they either transfer forces hydraulically or lack mechanisms to dissipate angular momentum effectively.
Innovation Solution
A protective helmet design featuring a hard outer shell with apertures covered by elastomeric diaphragms, a sliding inner shell, and fluid-filled bladders between the shells, connected by elastomeric cords that dissipate forces through elastic deformation and hysteretic damping, allowing the outer shell to float and absorb forces independently of the inner shell and brain.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If fluid-filled chambers are used to dissipate force through viscous friction, then energy dissipation increases, but the time to dissipate energy increases and substantial energy is transferred to the brain before fluid can be displaced
Solution Approach 1:
The patent introduces an expandable bladder as an intermediary element between the outer shell and inner shell. When impact force is applied, the bladder expands outward through apertures in the outer shell, directing force away from the braincase rather than allowing direct hydraulic transfer to the brain. This mediator approach resolves the contradiction by providing a different mechanism (bladder expansion) that acts faster than viscous fluid displacement while still dissipating energy.
Solution Approach 2:
The helmet is segmented into distinct functional zones: an outer shell with apertures, expandable bladders positioned at specific locations, an inner shell spaced from the outer shell, and cushioning pieces. This segmentation allows the impact force to be distributed and directed through multiple independent elements rather than relying on a single hydraulic fluid system, enabling faster response time while maintaining energy dissipation.
2Strength
If the inner shell is closely fitted to the outer shell, then structural strength is improved, but the ability to dissipate rotational forces and allow independent movement is reduced
Solution Approach 1:
The patent employs a dynamic design where the inner shell is spaced apart from the outer shell and connected by elastomeric cords rather than being rigidly fixed. This allows the inner shell to move independently and rotate relative to the outer shell during impact, dissipating rotational forces through the elastic deformation of the cords. The system transitions from a static rigid connection to a dynamic flexible connection that adapts to impact conditions.
Solution Approach 2:
The patent uses flexible elastomeric cords to connect the inner and outer shells, replacing rigid structural connections. These flexible elements allow relative movement and rotation between the shells while maintaining structural integrity, enabling the helmet to dissipate rotational forces effectively without compromising overall strength.
3Strength
If the outer shell is made rigid to protect against impact, then protective function is improved, but the shell cannot absorb forces independently and all force is directed into the head
Solution Approach 1:
The helmet structure is divided into separate functional components: the rigid outer shell provides impact resistance, while the inner shell spaced from it and connected by flexible cords can move independently. This segmentation allows the outer shell to maintain its protective rigid function while the inner components absorb and dissipate forces through independent movement and elastic deformation, preventing force concentration on the head.
Solution Approach 2:
The expandable bladders act as intermediaries between the rigid outer shell and the inner shell. When impact occurs, the bladders expand through apertures in the outer shell, absorbing impact energy and directing force away from the braincase. This intermediary mechanism allows the rigid outer shell to maintain its protective function while enabling force absorption without directing all force into the head.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The helmet effectively directs and dissipates both linear and rotational forces away from the brain, reducing the risk of concussive and torsional injuries by converting kinetic energy into heat, thereby enhancing protection against repetitive traumatic brain injuries.
Implementation Method 1
elastomeric cords that dissipate forces through elastic deformation
Implementation Method 2
elastomeric cords that dissipate forces through elastic deformation and hysteretic damping
Implementation Method 3
elastomeric cords that dissipate forces through elastic deformation and hysteretic damping
Implementation Method 4
fluid-filled bladders between the shells
Data Source
AI summary
A protective helmet including an outer shell including at least one aperture, an elastomeric diaphragm connected to an inner surface of the outer shell and covering the at least one aperture, an inner shell slidingly connected to the outer shell where the inner shell is spaced apart from the outer shell, and at least one expandable bladder positioned between the outer shell and the inner shell and operatively arranged to displace the elastomeric diaphragm in the at least one aperture of the outer shell.